过滤器和拦截器区别以及执行顺序

曾经终败给现在 2022-01-28 01:41 547阅读 0赞

1.  过滤器和拦截器区别  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoaWppdWppdTMz_size_16_color_FFFFFF_t_70]![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoaWppdWppdTMz_size_16_color_FFFFFF_t_70 1]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoaWppdWppdTMz_size_16_color_FFFFFF_t_70 2]  
    觉得这个总结的很好，所以用来借鉴借鉴  
    摘抄于网络，侵删
2.  过滤器和拦截器执行顺序  
    在SpringBoot中编写测试代码
    
     *  自定义过滤器
    
        /** * @Author: xiaoshijiu * @Date: 2019/5/22 * @Description: 自定义过滤器 */
        public class MyFilter extends HttpFilter { 
            @Override
            public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
                    throws IOException, ServletException { 
                System.out.println("Filter----before");  
                chain.doFilter(request,response);
                System.out.println("Filter----after");
            }
        }
    
     *  自定义拦截器  
        （有关SpringMVC的拦截器知识原理，可以参照我之前的博客）  
        [SpringMVC拦截器详解][SpringMVC]  
        [SpringMVC拦截器执行顺序原理解释][SpringMVC 1]
        
            /** * @Author: xiaoshijiu * @Date: 2019/5/22 * @Description: $value$ */
            public class MyInterception implements HandlerInterceptor { 
                @Override
                public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
                        Object handler) throws Exception { 
                    System.out.println("Interception----before");
                    return true;
                }
            
                @Override
                public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
                        ModelAndView modelAndView) throws Exception { 
                    System.out.println("Interception----before2");
                }
            
                @Override
                public void afterCompletion(HttpServletRequest request, HttpServletResponse response,
                        Object handler, Exception ex) throws Exception { 
                    System.out.println("Interception----after");
                }
            }
        
         *  配置拦截器和过滤器
        
            /** * @Author xiaoshijiu * @Description 自定义Mvc配置，实现全面接管SpringMvc的配置 * @Date 2019/5/13 */
            @Configuration
            public class MyWebMvc implements WebMvcConfigurer { 
                /** * 注册自定义的filter 就相当于在普通web工程中，在web.xml中注册的<filter></filter> */
                @Bean
                public FilterRegistrationBean myFilter() { 
                    return new FilterRegistrationBean(new MyFilter());
                }
            
                @Override
                public void addInterceptors(InterceptorRegistry registry) { 
                    // 添加自定义的拦截器
                    registry.addInterceptor(new MyInterception()).addPathPatterns("/hello");
                }
            }
        
         *  编写Controller，测试
        
            /** * @Author: xiaoshijiu * @Date: 2019/5/22 * @Description: 测试Controller */
            @RestController
            public class Mycontroller { 
            
                @RequestMapping("hello")
                public String hello() { 
                    System.out.println("hello...来了");
                    return "hello";
                }
            }
        
         *  打印结果  
            ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoaWppdWppdTMz_size_16_color_FFFFFF_t_70 3]  
            这里可以看到拦截器和过滤器的执行顺序，对照着上面他们的区别也是很好理解的  
            总结一下，执行顺序  
            ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoaWppdWppdTMz_size_16_color_FFFFFF_t_70 4]  
            这里还有一个问题就是发送`/hello`请求`filter`被执行了两次，我们可以获取url来判别一下  
            自定义过滤器添加代码
        
            HttpServletRequest servletRequest = (HttpServletRequest) request;
                    System.out.println(servletRequest.getRequestURI());
        
        可以看到SpringBoot项目会发送图标的请求（/favicon.ico）  
        ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoaWppdWppdTMz_size_16_color_FFFFFF_t_70 5]  
        最后在补充一下，request获取请求的一些方法的内容  
        ![在这里插入图片描述][20190522233919536.png]

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[SpringMVC]: https://blog.csdn.net/shijiujiu33/article/details/88138692
[SpringMVC 1]: https://blog.csdn.net/shijiujiu33/article/details/88146502
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[20190522233919536.png]: /images/20220128/afb5b173405a456ea0edb865f25ee642.png